Valve



United States Patent O 3,191,626 VALVE Kurt W. H. Leibfritz, Norridge, Ill., assignor to Parket- Haunifin Corpration, Cleveland, Ohio, a corporation of Ohio Filed Dec. 13, 1962, Ser. N0. 244,508 13 Claims. (Cl. 137625.69)

This invention relates to valves and'more parti cularly I0 a valve having resilient sealing men1bers.

The invention is particularly adap ted to valves of the spool type in which the spool has grooves carrying resient sealing membrs for sealing against th3 all of the bore in which the spool is mounted.

It is an object of the inve ntion to provide a spool valve having resilient sealing members carried in grooves on -ihr: spool in which the bottorns of the grooves are vented in a manner for preventing blow out of the resilient mombens from the grooves byfluid pressure.

lt is another object to providea valve of the type described in which the groov bottoms are vented to either of two low pressure zones in the valve depending upon which of the zones at that moment has the lower pressure.

It is another object to provide a valve df-the type des cribed in which venting of the groove carrying a resilient sealing ring is ziccomplishedthrough a bleed Passage and where in the bleed passage is normally closed by a valv ing device which is responsive to a differential in pressure between the bleed passage and a low pressum zone in the valve for opening the bleed passage.

It is another object to provide a valve of the type described in which O-rings of rubberlike material are Utilized as the seal on the valve spool which is to be vented and for the valving device which controls the bleed assage. 7

Other objects of the invention will b e apparent from the following description and from the drawings in which,

FIG. 1 is a view, partly in kross section, of a solenoi d pllot operated spool valve ernbodying the invention and FIG. 2 is an enlarged fragmentary view, partly.in sei:-

qion, of the spool.

The valve asse mbly includs a manlfold housing 10 attached to a main valve housing 11 and a solonoid 013erated pilot valve section l2 which is also attachod to main connected by a passage 14 with a pressure chamber 15 within the main valve. An exhaust port 16 is connectcd by means of pi1ssages 17 and 18 with passages 19 and 20,

the latter boing connected Witl1 exhaust charnbers 21 and 7 22, respectively.

On an opposite face; of housing 10 there is a cylinder port 23 connected by passage 24 with a cylinder passage 25. Theta is also a cylinder port 26 c onnected by mfcans of a passage27 With cylinder passage 28. As shown schematically, cylinder ports 23 and 26 may bc conxiected by rneans of pipe lines 29 and 30 with opposite ends of a fluid pressure operated motor 33 having a piston 33a.

' Restrlctor valves 31 and 32 are mounted for adjustable throttling of exhaust flow from passages 19 and t0 passage 18, resptictiyel3', for controlling. the speed with which piston 33a rnay reciprbcate.

Pressure pzissage 15 has a pair pf passages 34, 35 leading therefrom and respectively comrnunicating by. way of passages 36, 37 in pilot valve housing 12 With a pair of solenoid operated. pilot. valves housed .therein. Thus, passage 36 leads to a valve seat 38 and passa ge 37 leads to avalve seat 39. There are also valve seats 40, 43 in pilot valve sectionl2, eak:h of which comrnunicates wifh a passage 44. The latfter1's connected bymeans of passages 45 and 46 with exhaust chamber 21.

-Solenoid afmatures 47 and 48 serve as valve elements valVe 11. The manlfold housing 10 has an inlet port 13 -with the valve bore.

3,191,626 Patented June 29, 1965 for alternately opening and closing the respective seats 38, 40 and 39, 43. When the solenoids are not energized,

spring 49 normally seats pilot valve 47 on seat 40 and spring 50 normally presses ilot valve 48 against seat 43 to close off exhaust passage 44 from the interior of the two solenoid valves. At this filme armatures 47, 48 are unseated from seats 38 and 39 respectively.

Main valve housing 11 has a pair of sleeves 53, 54 therein which With openings 55, 56 form a valve bore in lwhich spool valve 57 is slidably mounted. Sleeve 54 has radial openings 58 which communicate with annular exhaust chamber 22 surrounding sleeve 54. Likewise, sleeve 53 has radial openings 59 communicating With like exhaust chamber 21. Sleeve 53 has smooth bore portions 60, 61 on opposite sides of openings 59 and sleeve 54 has smooth bore portions 63, 64 on opposite sides of openings 58.

Pressure assage 15 surrounds the valve bore and communicates therewith, as do cylinder passages 25, 28.

- spool as hereinafter described.

A djacont full diameter portion 73 is a button 76 loose- 1y fitted within bore 60 and a washer 77 of greater diameter than this bore, and a spring 78 which bears upon washer '77. There is a like button 79, washer 80, and spring- 83 adjacent full diameter portion 68.

As shown in FIG. 2, full diameter portion 74 has an annular groove 84 therein for receiving O-ring 85. The O-ring is retained within the groove by bending over the -si de Walls of the lattr, as indicated at 86, 87 so that the opening of the groove is narrowerthan the width of the O-ring. In addition, the side wallsof the groove, either at or below retaining lips 86, 87, make sealing contact with the Q-ring' so that fluid linder pressure along the exterior of the O-ring does not have ready access to the bottom of groove 84. A passage 88 connects the bottom of groove' 84 with a chamber 89 formed with.in valve spool 57. There'is a like O-ring 85, groove 84,; and relief passage 88 foreach of Ihe enlarged portions 69, 70 and 75. 4 Reduced diameter portion 67 has a groove 90 which inall positions of spool 57 is e qposed toopenings 59 and hence to exhaust chamber 21. A bleed or relief passago 93 connects the bottom of groove 90 With chamber 89 An Q-ring 94 of greater width than groove 90 seats on the edges of the groove.with a slight stretch fit so that lt Will*nornially close the groove and extend part way therein .to retain .its osition 011 spool ortion 67.

Reduced diameter portion 65 has a like groove 95,

- O-ring96, and a bleed passage 97.

In operation, with both sb1enoids 51, 52 de-eriergized,

springs49', 50 hold armatures 47, 48 against seats 40, 43 'for cl0sing 01T exhaust passage 44. Fluid under pressure from assage 15 mkes its way through Passages 34,

36, seat 38, around armature 47, through passages 98 and 99 to the outer (and face of full diameter portion 73. At the sme Iime, pressure fluid flows through passages 35, .37, seat 39, around armature 48 and through passages 100 and 103 to the outer face of full diameter portion 68. Thus there is equal pressure acting on opposite ends of spool 57 and the latter Will be in the neutral position as shown. At this time springs 78 and 83 are prevented by washers 77 and 80 from exerting any pre ssure upon the spool.

With valve spool 57 in neutral position, pressure fluid in passage 15 is blocked by full diameter portions 70, and 75 with the O-rings 85 therein establishing sealing contact in bore portions 55 and 56. Meanwhile, full diameter portions 74 and 69 isolate cylinder passage 28 frorn 'exhaust charnber 21 and cylinder assage 25 from exhaust chamber 22, respectively.

When sol-enoid coi1 51 is energized, armature 47 moves 10 the rig'nt against Saat 38 t clcvse passage 36 and cut off supply 0f pressure fluid to the -outer end 015 full diameter spool portion 73. At the sarne time, arrnature 47 moves aw=ay from sea-t 40 I0 open exhaust passage 44 and thus permit exhausting of the pressure fluid from the unter face or full diameter portion 73 to exhaust charn=ber 21 by way 0f p=assages 99, 98, seat 40, and passages 44, 45, and 46.

'The pressure on the outer fiace of full diamete-r portion 68 wchen causes va1ve spool 57 to move to the right, compressing spring 78. In this position, fu1l diameter portion 75 en-ters bore port-i0n 61 and full diameter pontion 69 enters bare portion 56 so that pressure fluid will flow from pa-ssage 15 -to cyldnder p-ort 28 while fluid from cylinder pa ssage 25 flows int=o exhaust chamber 22, thus oausing piston 33a t-o move the lef=t.

Dc-energ-izing 0f solenoid 51 permits spring 49 10 retu rn .arm ature 47 to seat 40 for cutting off exhaust passage 44 and again opening scat 38 to permit pressure fluid -t 0 flow to the unter face 015 fu1l diametcr spool portion 73 --for balaucing the fluid pressure acting on the upposite end of the .spool. -co neutral.

In a similar manner, energizing of solcnoid 52 causes This perrnits spring 78 o0 return the spool spool 57 to move to the left"f0r connecring pressure pass-age with cylinder p0*rt 25 and connecting cylinder pas- 'sa-ge 28 with exhaust charnber 21 for causing piston 33a 10 move to the right. V

In the variou-s positions cf spool 57 the O-rings 85 will at tirnes have one side of thei=r outer surfaces exposed to fluid unde-r h-igh pressure and the other side of the outer surfaoes exposcd to a lower pressure. In the event fluid should 1eak past the O-ring into the bottom of groove 84, there would .be a t-endency for the pressure of the fluid in the .b0toorn of the groove to blow the O-ring out of the groove and this would occur when the Oring passes out of a bore portion into a passage portion of lower pres'sure surrounding the valve bore. T0 prevent such .b10w cut,

the bott-omof each groove 84 i-s vented by means cf passages 88, chamber 89, bleed passa-ges 93, 97, and grooves 90, 95 exhaust chrarnber 21, 22.

As previously indicated, groove 90 is at all times ex- -posed to exhaust charnber 21, and groove 95 i-s at all times -exposed to exhaust chamber 22. O-rings 94, 96 act as -check valves to normally close grooves 90, 95 but are responsive to dififerentials of pressure in groove 90 over that in chamber 21, and that in groove 95 over that in chamber 22, for -opening and closing such grooves 90, 95. Thus, when the pressure of leakage fluid in groove 90 is greater than pressure in exhaust chamber 21, O-ring 94 Will stretch slightly to open groove 90 and permit fluid t-o flow thercfrom into chamber 21. Likewise, when the pressure in groove 95 isgreater than that in exhaust charnber 22,

O-ring 96 Will stretch slighfly to open groove 95 and perm-it fluid thcrefnom- 10 flow into exhaust chamber 22.

It will be =seen that chamber 89 conuects all 0f the pas- -sages 88 with both grooves 90, 95. Al though in sorne finstances it is -suflicient to provi-de only one or the other 01 grooves 90, 95 sinoe both connect chamber 89 with an exhau-st port, there are other times in which it is desirable -co have both. Thus for example, when restrict-or valve 31 is positioned for throttling exhaust flow from charnber 21 and passage 19 into passages 18, 17, and cut through port 16, t0 control the =speed of piston 33a in moving t0 the n'ght, there may be considerable back pressure developed Wi13hin chamber 21 and sleeve 53 whioh at times may even exceed the .prcssure in pas-sage 15. At such times O-ring 94 will remain seated on the edges of groove 90 to prevent back flow =of from within sleeve 53 10 ohnm- 10 the left, the pressure 013 exhaust fluid within -sleeve 54 can build up to exceecl p-rcssure cf leakage fluid in charmber 89, at which tirne exhaust pressure w ithin sleeve 53 will be 10W and pressure in charnber 89 will .be rclieved &hrough pas-sage 93 and the unseating of O-ring 94. Thus either O-ring 94 or O-ring 96 Will unseat to pass 1eakage fluid from chambe-r 89 depending upon which of exhaust chambers 21 or 22 has the 1ower pressure at that instant.

Since O-rings 94, 96, rare a slight stretch-fit in their groovcs, the latter will be cldsed When the pressure in charnber 89 is lower'than in the respective exhaust charmber 21, 22.

F0r some installations O-ring-s 94, 96 rnay be dispensed wi th because either there may be no occasi-ons in which the back pressure in exhaust chambers 21, 22 would bu i1d up sufficiently -to cause unseating of Oring or becausc .there will be -suflic-icnt relieving actio-n j;hrough one of the 1b1eed passages 93, 97 to prevcnt detrimental build up of pressure in passage 88 when high back pressure develops in the exhaus t chamber 21 or 22 associated with the other of the bleed passagcs.

If desired, the ends cf spool 57 may be exhausted of pressure, instead of pressurized, when the solenoids are in de-energized conddtion. In such an arrangernent passages 34, 35 and 45 .a're omitted, chzimber 15 is connected to passage 44 and passages 36 and 37 are connect-ed to exhaust passa-ge 46. Then when the solenoids are both deenergized, springs 49 and 50 keeparmatures 47, 48 in position for c1nsing seats 40 and 43 and opening seats 38, 39 to connect both ends of spool 57 to exhaust assage 46. Upon energizing of solenoid 51, arrnature 47 closes the exhaust p assage for the right hand end of spool 57 a1 sea-t 38 and opens seat 40 fior admittin-g fluid under pressure to the right band end of. spool 57 to shift the lat1er 10 the left. Sirnilarly, spool 57 may be caused to move to the righ-t by encrgizing s-olenoid 52 iustead 0f solcnoid 51.

Abthough one form of the invention has been illust-rated, it is obvious that the invention as covered by the following claims may have varioi1s other detail forms.

1. In a valve, abody having a bore, a high pressure passage, a cylinder passa-ge, and first and second exhaust passages intersecting said bore at spaced locati-ons, a valve member shiftable in said bore and having spaced sealing and porting means for closing and opening oommunication between selected ones of said passages, first and second bleed passages in said valve mernber comrnunicating with each other and constantly exposed to said first and second exhaust pass21ges respectively, said -scaling meaus including a resilient mernber moun'ted in a groove in said valve member, passage means for directing fluid leaki-ng along said bare past said resilieut mernber to the bottom 0f said g1'00ve 10 said bleed passages, and valving means assooiated with each bleed passage and responsive to a higher pressure in the assooiated b1eed passage than in the corresponding exhaust passage for opening such bleed passa-ge.

2. A va1ve in accordance with c1aim 1 in which each 0f said b1eed p=assagc s inc-ludes an annular groove in seid valve mernber and each 0f said valvitrg means cornprises a resilient member for 0pening and clo-sing the re spective annlar groove.

3. A valve in accordance with claim 1, in which both said valving means is responsive o0 substantially the same Pressure differential for opening the respective bleed passage whereby the b1ced passage opposite the exhaust passage hav=ing the lower pressure will opcn first.

4. A valve in accord-ance with c1aim 1 in which a portion of the groove side Wall overlaps a porti0n of the resilient member for mechanically restraining the resil-ient member against displacement from the groove.

5. A valve in accordance with claim 1 in which each of said bleed passages includes an annul:ar groove in said va1ve member and each cf said valving means comprises a resilierrt O-ring surrounding the respective annular gmove and mov=able for opening and closing the same.

6. A valve in accord-ance with claim 1 in which at least one cf said bleed passages includes an annular groove in said valve member and said valving means associa-ted therewith comprises an O-ring of greater cross seetion diameter than the Width of the annular groove and said O- ring makes sealing contact wit-h the radially outer edges of said annular groove for closing the last mentioned bleed passage. v

7. A valve in accordance With clairn 1 in which each of said bleed passages includes an annular groove in said valve member and each of said valving means cornprises an annular -resilient member stret-ched ove-r the respective annular groove and making sealing concact wi-th the outer edges thereof, each annular resilient member being deforrnable out of such sealing contact by pressu1e 0f fluid within the associated annular groove.

8. A valve in accordance with claim 1 in which at least one of said bleed passages includes an annular groove in said valve member and the valving mean-s associated With said one b1eed passage comprise an annular resilient member movable into and out cf seating contaot with at least one side of said gr-oove for closing and opening the sarne, said annular resiilient menmber being out of contact with the bottom of said groove to form a space therebetween, said space being -connected to said pa=ssage means whereby leakage fluid -fr-om said passage means has access to the entire area 0f the annular resilient member exposd 150 said space for applying pressure to said annular resilient member for unseating the same.

9. A valve in accordance with claim 1 in which each 'of said ex-haust passages have a flow restrictor therein for controlling the rate at which fluid rnay be exhausted therethrough. A

.10. In a valve, a body having a bare, a high pressure passage interseeting said bare, cylinder passages intersectfing the bore on opposite sides of said pressure passage, first and second exhaust passages intersecting the bare beyond the cylinder passages, a v.alve spool shiftable in said bare and h-aving spaced fu1l and reduced diameter portions for respectively closing and opening communication between selecced ones of said passages, a charnber within said spoo1, a first b1eed passage leading from said charmber to a first of said re:luced diameter p0r-tions and 001istantly exposed to said first exhaust assage, a second bleed passage lea=ding frorn said chamber to .a second of said reduced diameter portions and constan-fly exposed t0 said second exhaust passage, a fu1l diarne-ter portion of said spool be-ing located on each side of said pressure passage when said spool is in one position, each of said last mentioned full diameter portions having a groove therein, a resilient sealing mernber in each groove, assage means connecting the bottom cf each cf said grooves With both of said bleed passages for conducting fluid leaking past said resilient members to said groove bottorns to said exhaust passages so as to vent the under side of said resilient mernbers t0 prevent fluid within said groove from blowing said resilient members from said grooves.

11. A va1ve in accordance with claim 10 in which there is a valving means carried by each of said first and second reduced diameter portions and responsive to differentials in pressure between the respective bleed and exhaust passages for ope-ning and closing the respective b1eed passage.

12. In a valve, a -body mern'ber having a valve bore and a plural-ity of fluid passages communicating therewith, one of said passages being a high pressure passage and first and second cf said passages other than the high pressure passage being 10W pressure passages, a valve membe1 in said .bore having me*ans for connecting said high pressu1e passage to one of said plurality of passages through said .b0re in one p-osition of said valve rnember, a bleed passage in one of said mem=bers constanfly exposed to said first lower pressure passage and a second bleed passage in said one mem-ber constantly exposed to said second lower pressure passage, sealing rneans for sealing said valve member With respeet said body to prevent passage cf fluid from said high pressure Passage through said bore to said other passage in another position of the va1ve member, and passage means in one of said mernbers communicating With the sealing means for directing fluid leaking f1om said high pressure assage past said sealing means 110 both cf said bleed passages, a differential pres sure operated valve device associatecl With each of said bleed passages and oper.able for direct-ing the flow of said lea-kage fluid to the respective 10W pressure assage when the pressure of the leakage fluid exceeds the pressure of fluid within such 10W pressure passage.

13. In .a valve, a body member having a va1ve bore and a plurality of fluid passages communicating therewith, one cf said p-assages being a high pressure passage and first and second of said p:as-sages other than the high pressure passage being 10W pressure passages, a valve member in said .bore having rneans for connecting said high pressure passage t-o one cf said plurality of passages through said bare in one position of said valve memher, a bleed passage in one of said members constantly exposed to said first lower pressure passage and a second bleed passage in said one member constantly exposed to said second lower pressure passage, sealing means for sealing said valve member with respect to said body to prevent passage of fluid from said high pressure passage through said bore t0 said other assage in another osition of the valve mernber, and passage means in one of said members communicating with the sealing means for directing fluid leaking from said high pressure p-assage past said sealing means to both of said bleed passages, there being a member of resilient material for opening and closing each of said bleed passages in response differentials 05: pressure in the respective bleed and 10W pressure passages. 

1. IN A VALVE, A BODY HAVING A BORE, A HIGH PRESSURE PASSAGE, A CYLINDER PASSAGE, AND FIRST AND SECOND EXHAUST PASSAGES INTERSECTING SAID BORE AT SPACED LOCATIONS, A VALVE MEMBER SHIFTABLE IN SAID BORE AND HAVING SPACED SEALING AND PORTING MEANS FOR CLOSING AND OPENING COMMUNICATION BETWEEN SELECTED ONES OF SAID PASSAGES, FIRST AND SECOND BLEED PASSAGES IN SAID VALVE MEMBER COMMUNICATING WITH EACH OTHER AND CONSTANTLY EXPOSED TO SAID FIRST AND SECOND EXHAUST PASSAGES RESPECTIVELY, SAID SEALING MEANS INCLUDING A RESILIENT MEMBER MOUNTED IN A GROOVE IN SAID VALVE MEMBER, PASSAGE MEANS FOR DIRECTING FLUID LEAKING ALONG SAID BORE PAST SAID RESILIENT MEMBER TO THE BOTTOM OF SAID GROOVE TO SAID BLEED PASSAGES, AND VALVING MMEANS ASSOCIATED WITH EACH BLEED PASSAGE AND RESPONSIVE TO A HIGHER PRESSURE IN THE ASSOCIATED BLEED PASSAGE THAN IN THE CORRESPONDING EXHAUST PASSAGE FOR OPENING SUCH BLEED PASSAGE. 